The Securities and Exchange Commission is also questioning the forthrightness of SunEdison's disclosures. The Wall Street Journalreported on Monday evening the SEC is probing how SunEdison presented its cash balances to investors, a crucial piece of financial information given its over $11 billion debt load. That the SEC is investigating SunEdison's disclosures shouldn't be a surprise.

After all, the company has twice delayed an annual 10-k filing, first because its own executives raised questions into the veracity of its reported financial condition, and then because of a previously unreported IT glitch.

Specialist Gregg Maloney works at his post on the floor of the New York Stock Exchange, Tuesday, March 8, 2016. (AP Photo/Richard Drew)

Those who paid close attention to SunEdison's troubles have long warned that the company's problems could run deep.

Since the fall, CreditSights analysts Greg Jones and Andy DeVries have criticized SunEdison for what they see as misleading financial disclosures. Notably, these analysts questioned SunEdison's changing classification of $740 million in non-recourse debt, which the company eventually characterized as recourse. In a one-on-one call, CreditSights says SunEdison CFO Brian Wuebbels chalked up this mis-characterization to a "clerical error."

They also took objection to a Nov. 10 company presentation in which SunEdison said it had $1.4 billion in available cash, a misleading disclosure according to CreditSights because most of that cash was tied up to specific solar projects, or was contingent on future construction plans.

"Our view has been that SunEdison's liquidity position should not include restricted cash," CreditSights stated in a Mar. 1 report reacting to SunEdison's delayed 10-k. It's one thing if a billionaire hedge fund manager is suing you or a bond research firm raises red flags, it's another if the SEC is launching a probe. (The SEC declined to comment.)

Still, Tepper's lawsuit may be as relevant as ever, even as SunEdison hurtles towards what looks like the biggest bankruptcy in U.S. solar history. A filing Tuesday morning warns "there is a substantial risk that SunEdison will soon seek bankruptcy protection."

His campaign seeks to sever ties between TerraForm and its controlling shareholder SunEdison. It was launched in December after SunEdison took de-facto control over TerraForm's board of directors to help close a $1.9 billion acquisition of residential solar developer .

When SunEdison delayed filing its 10-k on Feb. 29, it caused banks to pull Vivint-related deal financing and the acquisition quickly collapsed. In the aftermath, Vivint's controlling shareholder Blackstone Group sued SunEdison seeking the full value of their original merger agreement. Without the Vivint deal and SunEdison quickly fading from the TerraForm picture, one would imagine Appaloosa's Tepper is taking a victory lap. But that's not the case.

TerraForm's board continues to be controlled by SunEdison-nominated directors. Meanwhile, SunEdison's CFO Brian Wuebbels is set to become TerraForm's permanent CEO in April. And worse yet, TerraForm's financial picture is a complete black hole. It too delayed filing a 10-k in February due to accounting issues at its parent, SunEdison, and put a hold on announcing a quarterly dividend (the lifeblood of a yieldco).

On Tuesday morning, TerraForm Global, another yieldco associated with the cratering SunEdison empire, warned investors it will delay filing a 10-k due to accounting and financial issues at its parent. This caused TerraForm Global shares to tumble over 20% on Tuesday morning. SunEdison shares fell 40% to below $1.

There is one major difference between TerraForm Global and TerraForm Power.

Since SunEdison hit financial difficulty in late 2015 and early 2016, TerraForm Power has been seen by investors like Tepper as the cleanest asset in what once was the fastest growing renewable energy developer in the United States. Given SunEdison's record of faulty disclosures; however, there's a major risk that the yieldco simply is the last clean shirt left to be sullied in this stock market disaster.